Solar installation

I am thinking about adding a small solar system to our 2350.  I am looking at the Renogy 100 Watt Monocrystalline Solar Panel kit from Amazon, complete with controller.  I am familiar with the math and charging rates of these kinds of installations and I know that 100 watts is pretty minimum.  All we really want from the system is a slow trickle charge for our battery bank when we are boondocking for several days.  Having come from a B Roadtrek, we would take day trips in the RT which recharged our batteries.   There is nothing less desireable than the sound of a genset in a national forest IMO.  BTW, I have changed all the incandescent bulbs in the PC to LEDs which is a big deal for us as to how we use power when we camp.   Where we go, there is no over the air tv and we seldom use any of the entertainment stuff other than the radio (remember those primitive devices?) for a little news.  No cell service where we go most of the time in the summer (way back in the NM and CO mountains). 

I searched these PC forums for solar and got some great ideas on the installation.  My only hesitation is drilling into that pristine roof.   It was noted (and a schematic was shown for a different model) that the PC construction has metal cross members every two feet across the roof for strutural integrity.  Obviously, you would need to mount (or a least partially mount) to those.  One post I researched indicated that those supports are also used for a wiring chase for some lights.  Sounds nasty to drill into if you hit a wire.  Is that in fact the case?  I understand the roof to be a thin fiberglass or similar material over plywood but I have no idea of the plywood thickness.  Anyone know how thick? 

Also, anyone that has done their own installation more recently than those posts (some of which are a couple of years old), do you have any tips or thoughts to suggest?  I plan to over engineer the mounting by using the standard Z mounts to attach to flat aluminum stock a couple of inches wide, mount the stock into the roof and then also use a good RV sealant/glue the length of the aluminum stock (1/8 inch thick by 2 inches by 48 inches) to further assure integrity of mount.  I have done a lot of mods on Bs and Cs over the years, so I can figure out the wire runs, etc.  Just properly attaching that puppy is my biggest concern.  I suspect finding the metal cross pieces in the PC frame will be pretty easy with stud finders or magnets. 

Any ideas, thoughts, suggestions or personal experiences would be appreciated.   Perhaps I also need to call PC and double check with them about the wire chases. 

I just got a braking and towing system for our new Cherokee Trailhawk and so I don't want to spend much for a small solar assist to charging.  I figure if I like the 100 watt system, I will add another panel before fall.

Paul

Kermit at the factory knows the answers to all your questions. He has been very helpful to those that call him.

Kermit, definitely.  Even Earl could probably send you some schematics/drawings, or even a short video of the areas you are looking at.

There is a new model 2450 for sale on the PC web page that apparently has solar.  It doesn't show the panels, but does show a control/monitor panel in one of the pictures (I think it's right near the main coach door stairwell). Wonder what equipment they use and how they ran the wiring for that.

  - Mike

The aluminum structure has 24" spacing. The easiest way I found to see where they are is to climb up on the roof on a humid morning. There will be lines of dew where each structural member is. Mark with ink pen.
Aluminum is non-magnetic.

I've done three different RV's with solar where I drilled into the roof, use Dicor to seal, never ever had a leak.

There is wiring in the structure. Each florescent fixture that Phoenix installs is attached to one of these channels.

Solar is the best way to charge batteries as long as the charge controller puts out 14.7 to 14.9 volts which the batter manufacturer recommends.

Well, I installed the 100 Watt Monocrystalline Solar Panel kit from Amazon on the roof and just got back from two weeks boondocking in Northern New Mexico.   We were parked in partial shade but the daylight sun was intense.  We were in the mountains at about 8000 feet.   I was very pleasantly surprised at just how well this little $180+ package worked.  It kept my batteries topped off and refreshed just fine.  I was more than surprised that there was a few amps flowing even when the panels were mostly covered by filitered sunlight from created by the trees.   This turned out to be a really good project.  Of course, the installation took about three times the length of time I anticipated, as usual for my projects.   I may buy another 100 watt panel and add it up there on the roof with the first one.   For boondockers, this is a really good panel at a very good price, compelte with cables and controller.

I installed 3 100 watt panels on mine.  I used Kermit's roof drawing to hit the studs. Unfortunately, I used too long screws and pierced the AC wire.  No harm done as we didn't order an AC.  But if we ever feel we need one, we would have to do some fancy wiring.

I think I would try what others have done by just silicon'ing the panels to the roof on proper standoffs.  Thereby eliminating the wiring problem.

Denny & Barb...........I tried to hit the studs with limited success.  I took the finish covers off the Fantastic and the bathroom vent to find a couple of the studs.  You can see them when you take the covers off.  Still, it is a stretch to find them and they are clearly used as wiring chases.   SO, I mounted the solar panel to two 1 1/2 inch wide by 48 inch long buy 1/8th inch thick pieces of aluminum stock using the four Z mounts that came with the panel.  Then, I applied roof sealant to the bottom of the two struts and positioned it on the roof.  Then I screwed self taping #10 by 3/4" screws through the struts and into the roof, penetrating the roof material and the underlying (thin) plywood.   In the couple of instances where I could hit the studs, I used 1 1/4" screws, figuring they would not go all the way to the bottom of the aluminum stud/chase.   The studs I penetrated carried only 12v wire.   Apparently, this worked.   After doing all that, I applied a liberal amount of roof sealant (three caulking tubes worth) to the tops of the struts flowing it onto the exterior roofing about a half an inch on all sides and covering all the screws.  WHEW!  I let it set a few days, drove up the interstate at 70 mph and inspected it.  No problems.  We just got back from a 1500 mile trip and I inspected it several times and am convinced it is really up there tight. 

I am sure there is a better, more appropriate way to do this, but it worked for me using this method.  My fear was hitting the wiring.  Thanks to folks on this forum for furnishing me the roof schematic and some other ideas. 

Paul

The price are really coming down on the frameless/bendable panels too.  $219 for 100w Renogy panels.

http://smile.amazon.com/Renogy%C2%AE-Monocrystalline-Bendable-Solar-Panel/dp/B00IK19VF6/

Currently I have a Renogy 100 rigid panel as a portable setup but would love to get some of those bendy ones on the roof too.  Love the 3# weight!

Here's my portable setup:
http://gailsails.blogspot.com/2014/03/my-solar-setup.html

Today I installed another panel, this time using the Renogy flexible 100 watter racephoto mentions in the post immediately above.  This thing only weighs four pounds!  Hooked the existing Renogy 100 watt panel together with this one with some Y connectors from Amazon.  

Put this down with 3M VHD mounting tape.  WOW.  First time I had used that stuff.  It is like contact cement from the standpoint that you don't get second chances!  It was in the high 70s here today and full sun.  I was amazed how the charging (amps) went up because, of course, it just doubled.  The PC has been in the storage garage since June 15, so the coach batteries would have naturally not been fully charged.  I was pumping 13.7 volts into the batteries and they charged fully very quickly.   The little Renogy controller that came in the kit with the first panel I installed seems to be working very well.  

The first two weeks of June we were boondocking and the one panel really worked great, particularly since we were camped in two different places in the National Forest in shady spots.  We never used the generator except for the convection/microwave and never had to use it to recharge the batteries.   I suspect with two panels now it will meet all our needs.   Changing the reading lights to LEDs really helps with the heat and power consumption.  

We are going out to Colorado in a few weeks and will be boondocking above 10,000 so we will be using the furnace in the mornings.  Those things are a real 12v power consumer.  It will be nice to have full batteries every morning.  I found out long ago that the secret to making these deep cycle batteries last years is simply not to discharge them very deeply.  I get nervous if the meter falls below 12.0 and never let it get much lower.   I got seven years out of my batteries in my previous rv prior to buying this PC last fall. 

Paul

Just a report on the performance of my two Renogy panels discussed earlier in this thread.

Two weeks just completed of boondocking high in the Rockies (mostly above 9,000 feet) and lots of useage of the electrical system and solar panels for recharging.   I could not be more pleased with this addition.  Even on the days when it was mostly cloudy our batteries stayed adequately charged.  I monitored the system frequently to make sure how the panels were working.  The heater (a real power eater) was used quite a bit since it was generally in the mid to high 30s in the mornings.  We were camped in a couple of spots on this trip and the rig was in the shade for over half the day, sunny for half the day (on good weather days).    We did change campsites from Colorado to New Mexico (one week in each state), so a couple of hundred miles driving assisted the charge.   

All those years we did this and fretted about battery levels are now history.  Solar is great!

Paul

Thanks Paul for the solar update on your rig. Certainly not a mistake to add solar to any unit. We do mostly dry camping so we ordered our PC with 4 batteries and no generator, and thus no AC ether. Haven't seen a problem in two years with this setup. Solar does what we need, and keeps us comfortable.

Tomorrow we are heading to Cheyenne, and later in the week to the Medicine Bow mountains where the campground elevation is around 11k.

We us lots of power I think anyway... I'm a ham radio guys that uses his 100 watt radio maybe 3 times a day. Also my wife likes lot of dvd's playing. When the mornings are at 32f we use the propane heater.

Weather we are in the sunny southwest (ariz/nm) or Wyoming, or Wisconsin, dry camping with the solar keeps the 4 batteries at or near 100% at all times and conditions. Now those of you with two batteries, will notice a slight less than this.  But that is ok. Batteries are designed to be cycled.